This invention relates generally to a flow sharing hydraulic system and, more particularly, to swing speed compensation for such a system.
Flow sharing hydraulic systems have been known in the art in recent times. Typically, these systems are used to control the movement of large swinging booms, such as a backhoe device. These systems utilize a metering spool that can be slidably engaged within a flow sharing valve to alter the path of the hydraulic fluid and, consequently, the movement of the swinging boom.
It is well established in the art to use a metering spool to control the function of a swinging boom. In a flow sharing hydraulic system, the metering spool has a solid center and multiple segments of different cross-sectional areas. Depending upon the position of the metering spool within the flow sharing valve, hydraulic fluid flow is provided to the system proportionally according to the cross-sectional area of the engaged segment of the metering spool.
One disadvantage of a flow sharing hydraulic system is that it provides constant fluid flow regardless of the angle and position of the swinging boom. Because of this constant fluid flow, the speed of the swinging boom is not smooth, particularly when starting or stopping the swing movement of the boom. The boom tends to have “jerking” swing movement upon starting or stopping of the boom.
To overcome this disadvantage, it has become well known in the art to add an anti-swag valve to the flow sharing hydraulic system. An anti-swag valve varies the fluid flow depending upon the angle and position of the swinging boom. Such a valve, however, is a very costly device that must be built on to the system.
It is therefore a principal object of this invention to provide a flow sharing hydraulic system that allows for variable fluid flow depending upon the angle and position of the swinging boom.
A further object of this invention is to provide such a system cost-effectively, without the need for anti-swag valves.
These and other objects will be apparent to those skilled in the art.